Table 1.

In vitro cytocidal and in vivo insecticidal activities of purified inclusion proteins from B. thuringiensis strains

StrainHemolysis on human erythrocytesCytocidal activityaagainst:
Human T cellsHuman lung cellsHuman uterus cervix cancer cellsInsect cellsInsecticidal activity againstb:
LeukemicNormalCancerNormalB. moriA. albopictusP. xylostellaC. pipiens molestus
84-HS-1-11++ (++)− (−)+ (±)++ (+)+++ (+++)− (+)− (+)
BFR1(pLEUK3.4S)++ (+++)− (−)+ (−)++ (+)+++ (+++)− (−)− (+)
  • a Alkali-solubilized, protease-treated inclusion proteins (124 μg ml−1) were examined for cytotoxic activities on MOLT-4 (human leukemic T cells), normal human T cells (primary culture), A549 (human lung cancer cells), MRC-5 (normal human lung fibroblast cells), HeLa (human uterus cervix cancer cells), BM-N (B. mori silkworm cells), and NIAS-AeAI-2 (A. albopictus mosquito cells). The results of microscopic observations are shown, and the levels of cytotoxicity, assessed by cell proliferation assay, are presented in parentheses. The degree of cell damage was graded as follows: high (+++), moderate (++), low (+), very low (±), and no damage (−).

  • b Purified inclusions were examined for insecticidal activity against larvae of the diamonback moth, P. xylostella, and the mosquito C. pipiens molestus. Ten fourth-instar larvae of P. xylostella were fed on an artificial diet (0.5 g) contaminated with 160 μg of purified inclusion. The test with C. pipiens molestus was done by introducing ten 4-day-old larvae into wells of 12-well tissue culture plates. Each well contained 160 μg of purified inclusion and 5 mg of diet in 3 ml of deionized water.